› Low hydraulic resistance
› Hydraulically ideal shape
› Opens with minimal water level rise
› Easy to install in new or existing structures
› Flap closed in rest position
(prevents access to open structures)
› Design ensures airtight seal
The Check Flap is designed to prevent backflows at sewer overflow locations as well as in retention tanks and basins. Receiving stream outlets can also be equipped with the Check Flap for flood control applications. In case of rising down-stream water levels the Check Flap will prevent water from getting into the sewer system. Overloading of sewer systems and sewage treatment plants is avoided and energy costs for pumping systems and sewage treatment are reduced.
The Check Flap is a pivoted check flap mounted over a rectangular discharge opening. In the rest position the Check Flap hangs vertically, due to its own weight, thereby closing and sealing the discharge opening. If the water level in the sewer or tank overflow rises, the hydrostatic pressure against the Check Flap causes it to open thereby allowing the water to flow over the sill. If the downstream water level rises, the Check Flap is pressed against the discharge opening so that no water can flow back into the sewer system. The Check Flap’s lightweight design makes it highly responsive to minimal water level changes while ensuring structural stability under high downstream water level conditions.